Remote control system



Dec. 2, 1930. ALLEN] 1,783,820

REMOTE CONTROL SYSTEM Original Filed Sept. 2 1925 Inventor:

Hugh BAHen,

y WJW H is Attorney.

Patented Dec. 2, 1930 UNITED STATES PATENT OFFICE HUGH E. ALLEN, OF SOHENECTADY, NEW YORK, ABSIGNOR '1'0 GENERAL ELECTRIC, COM- PANY, A CORPORATION OF NEW YORK 3 morn common SYSTEM Application filed September 2, 1925, Serial No. 54,152. Renewed Kay 2, 1930.

My present invention relates to aremote control system and more particularly to means for opening and closing a remote circuit by-means of high frequency current 6 superimposed on a system of distribution.

It is an obj ct of my invention to provide a remote contro system which may perform at least two functions by means of a single high frequency current supplied to the distributing system.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims: My invention itself, however, both as to its organization and methodof operation will best beunderstood by reference to the following specification taken in connection with the accompanying drawing in which the figure shows diagrammatically a circuit organization whereby my invention may be carried into effect.

Referring to the drawing, I have indicated at 1 a air of power mains of'a system of distribution. A. circuit 2, which is controlled by a mercury switch 3, may be located at any point of the system. The mercury switc includes a rectangular shaped block 4, made of any suitable insulating material such as wood or hard rubber. The block is pivoted at a central point 5 and is tilted about this point by means of a pair of relays 6 and 7 which are attached'to opposite ends of the block. Metal caps 8 and 9 are connected to opposite ends of block 4 by means of screws :10 and conducting washers 11. The screws serve additionally as means for connecting the terminals of circuit 2 to the metal caps. A circular glass tube 12 is cemented or otherwise firmly secured to the caps 8 and 9 which act as closures and supports or the tube.

Projecting from the end caps and extending toward one another within the tube 12-are a pair of conductors 13 and T4. A metallic plate '15, which is of substantiallythe same radius, as the inside of tube 12, and slightly greater inextent. than a semi-circle, is secured to the end of conductor 14. A small substantially semi-circular opening, not shown, is cut in the bottom ofplate 15 in order-to allow the mercury to flow from one end of tube 12 to the other. Conductor 13 is surrounded by a solidglass stem 16 which is provided with a hollow cup shaped portion 17 at the end adjacent conductor '14 in order to permit 'contact of the mercury with conductor 13;

Tube 12 is partially filled with mercury, the amount employed being sufiicient to slightly more than fill that portion of the tube including stem 16. Hydrogen gas is then supplied to the tube until a pressure of about one atmosphere is obtained, the hydrogen serving to reduce sparking when the circuit is opened or closed.

Relays 6 and 7 are supplied with current from a pair of alternating current mains 18, which may be connected to the mains 1, or any suitable source of power, the energizing circuit including a thermostat 19, a heater element20' and a switch'21. The thermostat 19 may be modified, if desired, to compensate for chan es in atmos heric temperature. Such a modi cation has een omitted, however, in the interest of clearness.

Switch 1 is operated by means of a winding 22. Current is supplied to a control circuit, which includes winding 22, by means through coupling condensers 25, and a secondary winding 26 tuned by a condenser 27 to the frequenc of the carrier current supplied to the distri ution system by a transmitter, not shown. Included in the control'cir'cuit is a disc arge device 28 comprising two dissimilar electrodes .29 and 30 enclosed in a receptacle 31. The receptacle 31 is filled with a suitable as such as neon or other inert gas at a de nite pressure, the particular gas and the pressure being so chosen that if a certain definite potential is impressed on electrodes 29 and 30 a discharge will take place and current will flow between the two electrodes as long as this potentialis maintained. Because of the dissimilar structure of the two electrodes, current-will flow in the control circuit in'one direction only;

,A constant potential is im ressed on the discharge device 28 by trans ormer 32 having 'a primary winding 33 and a secondary winding 34 included in the control circuit.

The potential impressed on the control circuit by transformer 32 maybe controlled by means of adjustable taps 35 and 36. The potential employed has a value somewhat lower than that at which a discharge will take place between the electrodes 29 and 30. lVhen high frequency current, however, is supplied to the coupling transformer 23, and impressed on the control circuit, the additional potential supplied by the received current will be sufiicient to produce a discharge through device 28 and cause current, supplied by secondary winding 34, to flow through device 28 and winding 22 as long as the high frequency current is supplied to the system. En'er'gization of winding 22 operates to close switch 21 to complete a circuitfrom mains 18 to relay 6 and heater element 20. When the current has flowed through the thermostatic element 19 and heater 20 for a predetermined period of time, the element 19 will move away from fixed contact 37 and engage contact 38 thus breaking the circuit to relay 6 and closing a circuit for relay 7. Energization of relay 7 tilts the mercury switch. The mercury runs through the small semicircular opening in the bottom of plate 15 and into the opposite portion of tube 12. Contact will be made by the mercury with conductors 13 and 14 until practically all the mercury has run into the opposite part of the tube. When this occurs circuit 2 will be opened.

When it is desired to close remote circuit 2, high frequency current is again supplied to the control circuit and relay 22 is again energized. Since the thermostatic element 19 normally closes a circuit for rela 6 through contact 37, relay 6 will be energized at this time to tilt the mercury switch to the position shown in the drawing. The mer cury will run through the small opening in the bottom of plate 15 and into that part of the tube containing the enclosed conductor 13. When the mercury fills the tube up to the cup-shaped opening 17 a circuit is completed through the mercury and contacts 13 and 14 toclose the remote circuit 2.

In order to energize relay 6 to close 'remote circuit 2, it is necessary to supply the high frequency current to the control circuit for a period of time, approximately three seconds in duration, this time being required to alter the center of gravity of the tube. When it is desired, however, to open the remote circuit the high frequency current must be maintained for an appreciable length of time during which element 19 will become heated to such an extent that it will move from contact 37 to contact 38, and energize relay 7 to tilt the mercury switch 3.

'It will be observed that but one high frequency need be employed in the operation of the control circuit. While the arrangement shown for controlling the remote circuit is particularly adapted for operation by carrier current it is, of course, clear that it may be employed in connection with electrical systems other than carrier current systems.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. In combination, a single electric circuit, means includin a plurality of electromagnets for controlling the circuit, means responsive to current of a certain frequency for closing a circuit to one of said electromagnets, and a time delay switch for opening the circuit to said one electromagnet and closing a circuit to another of said electromagnets.

2. In combination, a single electric circuit, means including a plurality of electromagnets for controlling the circuit, means responsive to current of a certain frequency for closing a circuit to one of said electromagnets, and thermostatic means for opening the circuit to said one electromagnet and closing the circuit to another of said electromagnets.

3. In combination, a plurality of electromagnets adapted to control an electric circuit, means for controlling the energization of said electromagnets, said means comprising a control circuit including a discharge device and a relay, a source of potential connected to said control circuit the value of the potential being somewhat lower than that required to break down the discharge device and produce a flow of current in the control circuit, and means whereby a high frequency current may be supplied to the control circuit to impress on the control circuit a potential great enough to cause current to flow therethrough from said source and energize said relay to close a circuit for one of said electromagnets.

4. In combination, a plurality of electromagnets adapted to control an electric circuit, means for controlling the energization of said electromagnets, said means comprising a control circuit including a discharge device and a relay, a source of potential connected to said control circuit the value of the potential being somewhat lower than that required to break down the discharge device and produce a flow of current in the control circuit, means whereby a high frequency current may be supplied to the control circuit to impress on the control circuit a potential great enough to cause current to flow therethroughfrom said source and to energize said relay to close a circuit for one of said electromagnets, and means for automatically opening the circuit for said one electromagnet after a predetermined period of time and closing a circuit to another of said electromagnets.

5. In combination, a plurality of electromangets, arranged to control an electric circuit, one of said electromagnets being arranged to control the opening of said circuit and another of said electromagnets being arranged to control the closing of said circuit, a single temperature controlled means normally in circuit with one of said electromagnets and adapted to be included in circuit with another of said electromagnets, and means independent of the circuit for governing the supply of current to the temperature controlled means selectively to control the energization of said electromagnets.

6. In combination, a plurality of electromagnets arranged to control a single electric circuit, means for closing a circuit to one of said magnets, and means in addition to said electromagnets, which is responsive to the flow of current'for automatically opening the circuit to said one electromagnet after a predetermined period of time, and closing a circuit to another of said electromagnets.

In witness whereof, I have hereunto set my hand this 1st day of September, 1925.

HUGH E. ALLEN. 

